1 #ifndef _UST_TRACEPOINT_H
2 #define _UST_TRACEPOINT_H
5 * Copyright (C) 2008 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
6 * Copyright (C) 2009 Pierre-Marc Fournier
7 * Copyright (C) 2009 Steven Rostedt <rostedt@goodmis.org>
9 * This library is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
14 * This library is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with this library; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * Heavily inspired from the Linux Kernel Markers.
25 * Ported to userspace by Pierre-Marc Fournier.
30 #include <ust/immediate.h>
42 const char *name
; /* Tracepoint name */
43 DEFINE_IMV(char, state
); /* State. */
47 #define PARAMS(args...) args
49 #define TP_PROTO(args...) args
50 #define TP_ARGS(args...) args
52 #define CONFIG_TRACEPOINTS
53 #ifdef CONFIG_TRACEPOINTS
56 * it_func[0] is never NULL because there is at least one element in the array
57 * when the array itself is non NULL.
59 #define __DO_TRACE(tp, proto, args) \
61 struct probe *it_probe_ptr; \
66 it_probe_ptr = rcu_dereference((tp)->probes); \
69 it_func = (it_probe_ptr)->func; \
70 __data = (it_probe_ptr)->data; \
71 ((void(*)(proto))(it_func))(args); \
72 } while ((++it_probe_ptr)->func); \
77 #define __CHECK_TRACE(name, generic, proto, args) \
80 if (unlikely(imv_read(__tracepoint_##name.state))) \
81 __DO_TRACE(&__tracepoint_##name, \
82 TP_PROTO(proto), TP_ARGS(args)); \
84 if (unlikely(_imv_read(__tracepoint_##name.state))) \
85 __DO_TRACE(&__tracepoint_##name, \
86 TP_PROTO(proto), TP_ARGS(args)); \
91 * Make sure the alignment of the structure in the __tracepoints section will
92 * not add unwanted padding between the beginning of the section and the
93 * structure. Force alignment to the same alignment as the section start.
95 * The "generic" argument, passed to the declared __trace_##name inline
96 * function controls which tracepoint enabling mechanism must be used.
97 * If generic is true, a variable read is used.
98 * If generic is false, immediate values are used.
100 #define __DECLARE_TRACE(name, proto, args, data_proto, data_args) \
101 extern struct tracepoint __tracepoint_##name; \
102 static inline void trace_##name(proto) \
104 __CHECK_TRACE(name, 0, TP_PROTO(data_proto), \
105 TP_ARGS(data_args)); \
107 static inline void _trace_##name(proto) \
109 __CHECK_TRACE(name, 1, TP_PROTO(data_proto), \
110 TP_ARGS(data_args)); \
113 register_trace_##name(void (*probe)(data_proto), void *data) \
115 return tracepoint_probe_register(#name, (void *)probe, \
120 unregister_trace_##name(void (*probe)(data_proto), void *data) \
122 return tracepoint_probe_unregister(#name, (void *)probe, \
126 #define DEFINE_TRACE_FN(name, reg, unreg) \
127 static const char __tpstrtab_##name[] \
128 __attribute__((section("__tracepoints_strings"))) = #name; \
129 struct tracepoint __tracepoint_##name \
130 __attribute__((section("__tracepoints"))) = \
131 { __tpstrtab_##name, 0, NULL }; \
132 static struct tracepoint * const __tracepoint_ptr_##name \
133 __attribute__((used, section("__tracepoints_ptrs"))) = \
134 &__tracepoint_##name;
136 #define DEFINE_TRACE(name) \
137 DEFINE_TRACE_FN(name, NULL, NULL)
139 extern void tracepoint_update_probe_range(struct tracepoint
* const *begin
,
140 struct tracepoint
* const *end
);
142 #else /* !CONFIG_TRACEPOINTS */
143 #define __DECLARE_TRACE(name, proto, args) \
144 static inline void trace_##name(proto) \
146 static inline void _trace_##name(proto) \
148 static inline int register_trace_##name(void (*probe)(proto), void *data) \
152 static inline int unregister_trace_##name(void (*probe)(proto), void *data) \
157 #define DEFINE_TRACE(name)
158 #define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
159 #define EXPORT_TRACEPOINT_SYMBOL(name)
161 static inline void tracepoint_update_probe_range(struct tracepoint
*begin
,
162 struct tracepoint
*end
)
164 #endif /* CONFIG_TRACEPOINTS */
166 #define DECLARE_TRACE(name, proto, args) \
167 __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args), \
168 PARAMS(void *__data, proto), \
169 PARAMS(__data, args))
172 * Connect a probe to a tracepoint.
173 * Internal API, should not be used directly.
175 extern int tracepoint_probe_register(const char *name
, void *probe
, void *data
);
178 * Disconnect a probe from a tracepoint.
179 * Internal API, should not be used directly.
181 extern int tracepoint_probe_unregister(const char *name
, void *probe
, void *data
);
183 extern int tracepoint_probe_register_noupdate(const char *name
, void *probe
,
185 extern int tracepoint_probe_unregister_noupdate(const char *name
, void *probe
,
187 extern void tracepoint_probe_update_all(void);
189 struct tracepoint_iter
{
190 //ust// struct module *module;
191 struct tracepoint_lib
*lib
;
192 struct tracepoint
* const *tracepoint
;
195 extern void tracepoint_iter_start(struct tracepoint_iter
*iter
);
196 extern void tracepoint_iter_next(struct tracepoint_iter
*iter
);
197 extern void tracepoint_iter_stop(struct tracepoint_iter
*iter
);
198 extern void tracepoint_iter_reset(struct tracepoint_iter
*iter
);
199 extern int tracepoint_get_iter_range(struct tracepoint
* const **tracepoint
,
200 struct tracepoint
* const *begin
, struct tracepoint
* const *end
);
203 * tracepoint_synchronize_unregister must be called between the last tracepoint
204 * probe unregistration and the end of module exit to make sure there is no
205 * caller executing a probe when it is freed.
207 static inline void tracepoint_synchronize_unregister(void)
209 //ust// synchronize_sched();
212 struct tracepoint_lib
{
213 struct tracepoint
* const *tracepoints_start
;
214 int tracepoints_count
;
215 struct cds_list_head list
;
218 extern int tracepoint_register_lib(struct tracepoint
* const *tracepoints_start
,
219 int tracepoints_count
);
220 extern int tracepoint_unregister_lib(struct tracepoint
* const *tracepoints_start
);
222 #define TRACEPOINT_LIB \
223 extern struct tracepoint * const __start___tracepoints_ptrs[] __attribute__((weak, visibility("hidden"))); \
224 extern struct tracepoint * const __stop___tracepoints_ptrs[] __attribute__((weak, visibility("hidden"))); \
225 static struct tracepoint * const __tracepoint_ptr_dummy \
226 __attribute__((used, section("__tracepoints_ptrs"))) = NULL; \
227 static void __attribute__((constructor)) __tracepoints__init(void) \
229 tracepoint_register_lib(__start___tracepoints_ptrs, \
230 __stop___tracepoints_ptrs - \
231 __start___tracepoints_ptrs); \
234 static void __attribute__((destructor)) __tracepoints__destroy(void) \
236 tracepoint_unregister_lib(__start___tracepoints_ptrs); \
242 * For use with the TRACE_EVENT macro:
244 * We define a tracepoint, its arguments, its printf format
245 * and its 'fast binary record' layout.
247 * Firstly, name your tracepoint via TRACE_EVENT(name : the
248 * 'subsystem_event' notation is fine.
250 * Think about this whole construct as the
251 * 'trace_sched_switch() function' from now on.
254 * TRACE_EVENT(sched_switch,
257 * * A function has a regular function arguments
258 * * prototype, declare it via TP_PROTO():
261 * TP_PROTO(struct rq *rq, struct task_struct *prev,
262 * struct task_struct *next),
265 * * Define the call signature of the 'function'.
266 * * (Design sidenote: we use this instead of a
267 * * TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.)
270 * TP_ARGS(rq, prev, next),
273 * * Fast binary tracing: define the trace record via
274 * * TP_STRUCT__entry(). You can think about it like a
275 * * regular C structure local variable definition.
277 * * This is how the trace record is structured and will
278 * * be saved into the ring buffer. These are the fields
279 * * that will be exposed to readers.
281 * * The declared 'local variable' is called '__entry'
283 * * __field(pid_t, prev_prid) is equivalent to a standard declariton:
287 * * __array(char, prev_comm, TASK_COMM_LEN) is equivalent to:
289 * * char prev_comm[TASK_COMM_LEN];
293 * __array( char, prev_comm, TASK_COMM_LEN )
294 * __field( pid_t, prev_pid )
295 * __field( int, prev_prio )
296 * __array( char, next_comm, TASK_COMM_LEN )
297 * __field( pid_t, next_pid )
298 * __field( int, next_prio )
302 * * Assign the entry into the trace record, by embedding
303 * * a full C statement block into TP_fast_assign(). You
304 * * can refer to the trace record as '__entry' -
305 * * otherwise you can put arbitrary C code in here.
307 * * Note: this C code will execute every time a trace event
308 * * happens, on an active tracepoint.
312 * memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
313 * __entry->prev_pid = prev->pid;
314 * __entry->prev_prio = prev->prio;
315 * memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
316 * __entry->next_pid = next->pid;
317 * __entry->next_prio = next->prio;
321 * * Formatted output of a trace record via TP_printf().
322 * * This is how the tracepoint will appear under debugging
325 * * (raw-binary tracing wont actually perform this step.)
328 * TP_printf("task %s:%d [%d] ==> %s:%d [%d]",
329 * __entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
330 * __entry->next_comm, __entry->next_pid, __entry->next_prio),
334 * This macro construct is thus used for the regular printf format
337 * A set of (un)registration functions can be passed to the variant
338 * TRACE_EVENT_FN to perform any (un)registration work.
343 int (*regfunc
)(void *data
);
344 int (*unregfunc
)(void *data
);
347 struct trace_event_lib
{
348 struct trace_event
* const *trace_events_start
;
349 int trace_events_count
;
350 struct cds_list_head list
;
353 struct trace_event_iter
{
354 struct trace_event_lib
*lib
;
355 struct trace_event
* const *trace_event
;
358 extern void lock_trace_events(void);
359 extern void unlock_trace_events(void);
361 extern void trace_event_iter_start(struct trace_event_iter
*iter
);
362 extern void trace_event_iter_next(struct trace_event_iter
*iter
);
363 extern void trace_event_iter_reset(struct trace_event_iter
*iter
);
365 extern int trace_event_get_iter_range(struct trace_event
* const **trace_event
,
366 struct trace_event
* const *begin
,
367 struct trace_event
* const *end
);
369 extern void trace_event_update_process(void);
370 extern int is_trace_event_enabled(const char *channel
, const char *name
);
372 extern int trace_event_register_lib(struct trace_event
* const *start_trace_events
,
373 int trace_event_count
);
375 extern int trace_event_unregister_lib(struct trace_event
* const *start_trace_events
);
377 #define TRACE_EVENT_LIB \
378 extern struct trace_event * const __start___trace_events_ptrs[] \
379 __attribute__((weak, visibility("hidden"))); \
380 extern struct trace_event * const __stop___trace_events_ptrs[] \
381 __attribute__((weak, visibility("hidden"))); \
382 static struct trace_event * const __event_ptrs_dummy \
383 __attribute__((used, section("__trace_events_ptrs"))) = NULL; \
384 static void __attribute__((constructor)) \
385 __trace_events__init(void) \
387 trace_event_register_lib(__start___trace_events_ptrs, \
388 __stop___trace_events_ptrs - \
389 __start___trace_events_ptrs); \
392 static void __attribute__((destructor)) \
393 __trace_event__destroy(void) \
395 trace_event_unregister_lib(__start___trace_events_ptrs);\
398 #define DECLARE_TRACE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
399 #define DEFINE_TRACE_EVENT(template, name, proto, args) \
400 DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
401 #define DEFINE_TRACE_EVENT_PRINT(template, name, proto, args, print) \
402 DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
404 #define TRACE_EVENT(name, proto, args, struct, assign, print) \
405 DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
406 #define TRACE_EVENT_FN(name, proto, args, struct, \
407 assign, print, reg, unreg) \
408 DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
410 #endif /* ifdef TRACE_EVENT (see note above) */
413 #endif /* _UST_TRACEPOINT_H */
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